1. Field of the Invention
The present invention relates to an apparatus for replacing a shock absorber for another in a McPherson's strut type suspension which is installed at the front drive of automobiles, and more particularly, to a shock absorber replacement apparatus which supports and compresses a coil spring in a strut type suspension, so that the coil spring can be stably compressed during performing a replacement work, and the replacement work can be performed in correspondence to various dimensions of shock absorbers, in order to replace a shock absorber constituting a strut type suspension for another.
2. Description of the Related Art
In general, a strut type suspension chiefly connects a wheel axle with a car body at the front drive of an automobile car and buffers and support a knuckle arm. The strut type suspension integrally includes a shock absorber and a coil spring in a strut, in which the upper portion of the strut is connected to the car body through a support and the lower portion thereof is integrally connected to a steering knuckle.
The strut type suspension absorbs impact transferred from the ground surface through wheels during running of the automobile car and attenuates vibration of the car body, to thus make riders feel comfortable. However, when a total running distance of an automobile car becomes longer or severe impact is applied to the front drive of the automobile car, a shock absorbing function of a shock absorber is lowered. Accordingly, if the shock absorber is broken, impact transferred from the ground surface is directly transferred to the car body, and thus a running steering function and a comfortable riding feel are lowered. In severe cases, the shock absorber should be replaced with a new one.
When a shock absorber is replaced with a new one, a strut type suspension should be primarily separated from a steering knuckle and a car body and then mount bolts and nuts which are connected with a support located in the upper end of a piston rod in the shock absorber should be released and dismantled from the support at the state where a coil spring is compressed. Then, the shock absorber should be separated from the strut and replaced with a new one.
The most difficult work is a coil spring compression work when a shock absorber is replaced with a new one. Accordingly, a coil spring compressor for compressing a coil spring in a shock absorber is disclosed in Korean Utility Model Publication No. 96-777 on Jan. 27, 1996.
In the coil spring compressor for use in a shock absorber replacement apparatus for an automobile car, a hydraulic cylinder is installed on a fixed frame installed in the upper portion of a strut column and a strut gripper is installed with an interval downwards. A support rod in which a clip unit which hangs up a coil spring and a compression clip are installed is installed elastically by a spring in the upper portion between the hydraulic cylinder and the strut gripper. The strut gripper which is located in the lower portion between the hydraulic cylinder and the strut gripper is connected with a piston rod in the hydraulic cylinder.
In the above-described prior art, a strut located in the lower portion of the strut type suspension is fixed to the strut gripper and then the hydraulic cylinder is operated at the state where the coil spring is hung up with the compression clip through adjustment of the clip unit, to accordingly compress the coil spring. Then, the upper portion of the shock absorber is elastically released from the coil spring, and thus the mount bolts and nuts of the shock absorber can be released and separated from the coil spring. Then, after the hydraulic cylinder is operated to release the compression of the coil spring and to thus then completely separate the coil spring from the shock absorber, a shock absorber for replacement is position and re-fixed in the strut gripper and then the existing coil spring is fitted into the shock absorber. Then, in the reverse process, the shock absorber can be completely replaced.
Although the conventional shock absorber replacement apparatus can conveniently and easily achieve a replacement work of shock absorbers through a manual work, it cannot efficiently perform a replacement work of shock absorbers and strut type suspensions of a variety of dimensions.
For example, the conventional shock absorber replacement apparatus can grip only a strut type suspension belonging to an allowable range of an inner diameter of a hinge-type tightening tool in a strut gripper. Accordingly, suspensions having an outer diameter larger than the inner diameter of the hinge-type tightening tool and different shapes cannot be replaced.
In addition, in the conventional shock absorber replacement apparatus, a hydraulic cylinder is installed in one side of a strut column and the hydraulic cylinder is used as a power source to perform a replacement work. In this case, the coil spring is structurally unstably compressed.